Seagoing craft



July 21, 1931. I w. R. BLAIR 1,815,286

SEAGOING CRAFT Filed May 16. 1930 Patented July 21, 1931 UNITED STATES WILLIAM R. BLAIR, OF WASHINGTON, DISTRICT OF COLUMBIA.

SEAGOIN G CRAFT Application filed May 16, 1930. Serial No. 453,007.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, AS AMENDED APRIL 30, 1928; 870 0. G-

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a sea going craft of that type having the load supporting hulls positioned beneath the disturbed sea surface and the load itself positioned well above the sea surface by strut members which do not 1 interpose sufiicient resistance to the waves to sroduce instability of the craft.'

bjects of this invention are to provide a craft of the type mentioned, in a practical form, which is extremely stable in heavy seas,

which automatically compensates the lift of the supporting hulls, which will not list if load is applied unevenly to the craft as a whole, and which will maintain its proper position or level in the water regardless of the weight of the load carried.

An important object of the invention is to regulate the automatic compensating means in such a manner that the submerged loadsupporting hulls or floats will be maintained at a predetermined level below the sea surface and at a suflicient depth to minimize the effects of wave action and surface currents. Other objects of the invention will appear as the description proceeds.

The drawings accompanying this-application illustrate diagrammatically one method of effecting the above objects, Fig. 1 being a side View of the craft in the water showing a View of the same partly in cross section; and

Figure 2 being a bottom plan view of Figure 1.

In these drawings there is shown load supporting hulls 1 positioned beneath the disturbed sea surface, andhaving upwardly extending struts 2, which project a load carrying platform 3 well up out of reach of any waves. To propel the craft through the water any type of motive power may be used the power units 4 connected to propellers 5 being merely suggestive.

' Although only one hull is shown in cross section, it is to be understood that the description which follows applies equally to all the hulls. The cross sectioned one shows a ballast chamber 6 communicating with the sea through an opening 7 and with a compressed air supply 8 through valves 9, and 10, the valves 10 operating as an air release. The valves 9 and 10 are controlled either or preferably by electric motors 11. These motors are energized by a current source, in this case a battery 12 which is connected in circuit, through switches 13, the same being located, one above and one below the mean level which it is desirable the craft as a whole should maintain. Line w-x of Fig. 1 indicates the mean levelof the sea surface which preferably should be maintained by the craft. The switches 13 are operable by thewater level maintained in a tube 14 which is open to the sea and preferably has a restricted water entrance 15 to prevent undue oscillation of the water in the tube. It will be seen that as the craft settles because of an increase in load, the valves 9 will be operated by the rise of water in the tubes 14 operating the upper of the switches 13 and will allow compressed air from the supply 8 to force water out of the hulls ballast chambers 6 and thus increase their buoyant force. If, on the other by hand 0 hand, the craft rises because of a reduced load 1 the lower of the switchesl3 will operate to release air from the ballast chamber through the release valves 10, allowing water to enter same and decreasing their buoyant force, the valves 9 being closed.

Preferably thehulls l have their ballast chambers interconnected by hollow members 16 through valves 17 for the purpose of equalizing the pressures existing in all to create an ever upward thrust of each. When the craft is being loaded and unloaded there is apt to be an uneven placement of the load causing the craft to list and in this case the valves 17 are closed, allowing the hulls to increase or decrease their buoyant force individually to compensate for unevenness of load. I This might also be desirable in caseofan accident to one of the hulls.

The foregoing description is brief and the drawings diagrammatic but one skilled in the art may readily reduce the same to concreteform to evolve a craft which will ac complish the objects as proposed, this being in accordance with the requirements of the U. S. patent statutes; but it is tobe understood'that the embodiment of the invention here disclosed is to comply with same and is not'intended to limit the scope of the appended claims.

Rudders are preferably used to control the direction of movement of the craft, one set being shown at 18 by way of example. Fins or'rudders may also be employed as at 19 to assist in maintaining the craft at a constant depth or level when under movement, and also to promote the stability of the chaft.

I claim:

1. A sea going craft comprising a loadcarryingsuperstructure; a plurality of supporting hulls positioned in the water beneath thedisturbed sea surface; struts connecting said superstructure and supporting hulls, and adapted to projectv with said superstructure above the sea'surface; and means positively operated with eachof said hulls to contml their buoyancy individually.

2. A sea going craft comprising a loadcarrying superstructure; a series of supporting floats adapted to be submerged in a position beneath the disturbed sea surface; struts connecting, said superstructure and supporting hulls; and adapted to project above the sea surface; fluid carrying means between said struts and floats; fluid supply 'meansand means responsive to loadvariations and controlled by fluctuations of the mean level of the sea surface to positively actuate said fluid supply means and automatically compensate the lift of said supporting floats. p

3. A sea going craft comprising in combination a load carrying component; a plurality of submerged hulls having connecting struts adapted to support saidload carrying component above the disturbed sea surface and having fluid-communication with said hulls; fluid means positively operative With each of said bulls and struts and responsive to load variations to automatically compensatethe lift of said hulls.

structure includin stant buoyancy and alower compartment hav ing variable I buoyancy; and means respons1ve to load variat ons on said superstructure and positively operative with said lower compartment to regulate the buoyancy of each of said floats.

6. A sea going craft comprising a loadcarrying superstructure; a plurality of supporting hulls adapted to be submerged beneath the disturbed sea surface; hollow struts connecting said superstructure and supporting hulls, and adapted to project with said superstructure above the sea surface 'a tube to indicate the meanlevel of the sea surface vertically disposed within each of said hulls and struts, said tube having communication with the sea at itslower end and open to atmosphere at itsupper end; fluidsupply=means for eachof said hulls to regulate buoyancy and electric circuits operative therewith; and switches in each of said circuits so positioned in each tube as to alternately respond'to fluctuations. of water level to control the operation of the ,fluid supply means.

7. A sea going craft comprising a loadcarrying' superstructure; a supporting suba plurality of supporting floats adapted to be submerged beneath the disturbed sea surface, each of said floats having a variablybuoyant ballast chamber; and fluid control means operative with each of said chambers to vary their lift selectively to compensate for'load variations on said superstructure.

In testimony whereof I aflix my signature.

R. BLAIR.

4. A sea going craft comprising a loadcarrying superstructure; a substructure including a plurality of supporting hulls sub merged beneath the sea surface; struts connecting said superstructure and substruc- 

